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Holeček M. Origin and Roles of Alanine and Glutamine in Gluconeogenesis in the Liver, Kidneys, and Small Intestine under Physiological and Pathological Conditions. Int J Mol Sci 2024; 25:7037. [PMID: 39000145 PMCID: PMC11241752 DOI: 10.3390/ijms25137037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2024] [Revised: 06/21/2024] [Accepted: 06/25/2024] [Indexed: 07/16/2024] Open
Abstract
Alanine and glutamine are the principal glucogenic amino acids. Most originate from muscles, where branched-chain amino acids (valine, leucine, and isoleucine) are nitrogen donors and, under exceptional circumstances, a source of carbons for glutamate synthesis. Glutamate is a nitrogen source for alanine synthesis from pyruvate and a substrate for glutamine synthesis by glutamine synthetase. The following differences between alanine and glutamine, which can play a role in their use in gluconeogenesis, are shown: (i) glutamine appearance in circulation is higher than that of alanine; (ii) the conversion to oxaloacetate, the starting substance for glucose synthesis, is an ATP-consuming reaction for alanine, which is energetically beneficial for glutamine; (iii) most alanine carbons, but not glutamine carbons, originate from glucose; and (iv) glutamine acts a substrate for gluconeogenesis in the liver, kidneys, and intestine, whereas alanine does so only in the liver. Alanine plays a significant role during early starvation, exposure to high-fat and high-protein diets, and diabetes. Glutamine plays a dominant role in gluconeogenesis in prolonged starvation, acidosis, liver cirrhosis, and severe illnesses like sepsis and acts as a substrate for alanine synthesis in the small intestine. Interactions among muscles and the liver, kidneys, and intestine ensuring optimal alanine and glutamine supply for gluconeogenesis are suggested.
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Affiliation(s)
- Milan Holeček
- Department of Physiology, Faculty of Medicine, Charles University, 500 03 Hradec Kralove, Czech Republic
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2
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Intestinal gluconeogenesis: metabolic benefits make sense in the light of evolution. Nat Rev Gastroenterol Hepatol 2023; 20:183-194. [PMID: 36470967 DOI: 10.1038/s41575-022-00707-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 10/27/2022] [Indexed: 03/02/2023]
Abstract
The intestine, like the liver and kidney, in various vertebrates and humans is able to carry out gluconeogenesis and release glucose into the blood. In the fed post-absorptive state, intestinal glucose is sensed by the gastrointestinal nervous system. The latter initiates a signal to the brain regions controlling energy homeostasis and stress-related behaviour. Intestinal gluconeogenesis (IGN) is activated by several complementary mechanisms, in particular nutritional situations (for example, when food is enriched in protein or fermentable fibre and after gastric bypass surgery in obesity). In these situations, IGN has several metabolic and behavioural benefits. As IGN is activated by nutrients capable of fuelling systemic gluconeogenesis, IGN could be a signal to the brain that food previously ingested is suitable for maintaining plasma glucose for a while. This process might account for the benefits observed. Finally, in this Perspective, we discuss how the benefits of IGN in fasting and fed states could explain why IGN emerged and was maintained in vertebrates by natural selection.
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Joly-Amado A, Soty M, Philippe E, Lacombe A, Castel J, Pillot B, Vily-Petit J, Zitoun C, Mithieux G, Magnan C. Portal Glucose Infusion, Afferent Nerve Fibers, and Glucose and Insulin Tolerance of Insulin-Resistant Rats. J Nutr 2022; 152:1862-1871. [PMID: 35511216 DOI: 10.1093/jn/nxac097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 01/19/2022] [Accepted: 04/26/2022] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND The role of hepatoportal glucose sensors is poorly understood in the context of insulin resistance. OBJECTIVES We assessed the effects of glucose infusion in the portal vein on insulin tolerance in 2 rat models of insulin resistance, and the role of capsaicin sensitive nerves in this signal. METHODS Male Wistar rats, 8 weeks old, weighing 250-275 g, were used. Insulin and glucose tolerance were assessed following a 4-hour infusion of either glucose or saline through catheterization in the portal vein in 3 paradigms. In experiment 1, for diet-induced insulin resistance, rats were fed either a control diet (energy content: proteins = 22.5%, carbohydrates = 64.1%, and lipids = 13.4%) or a high-fat diet (energy content: proteins = 15.3%, carbohydrates = 40.3%, and lipids =44.4%) for 4 months. In experiment 2, for centrally induced peripheral insulin resistance, catheters were inserted in the carotid artery to deliver either an emulsion of triglycerides [intralipid (IL)] or saline towards the brain for 24 hours. In experiment 3, for testing the role of capsaicin-sensitive nerves, experiment 2 was repeated following a periportal treatment with capsaicin or vehicle. RESULTS In experiment 1, when compared to rats fed the control diet, rats fed the high-fat diet exhibited decreased insulin and glucose tolerance (P ≤ 0.05) that was restored with a glucose infusion in the portal vein (P ≤ 0.05). In experiment 2, infusion of a triglyceride emulsion towards the brain (IL rats) decreased insulin and glucose tolerance and increased hepatic endogenous production when compared to saline-infused rats (P ≤ 0.05). Glucose infusion in the portal vein in IL rats restored insulin and glucose tolerance, as well as hepatic glucose production, to controls levels (P ≤ 0.05). In experiment 3, portal infusion of glucose did not increase insulin tolerance in IL rats that received a periportal pretreatment with capsaicin. CONCLUSIONS Stimulation of hepatoportal glucose sensors increases insulin tolerance in rat models of insulin resistance and requires the presence of capsaicin-sensitive nerves.
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Affiliation(s)
- Aurélie Joly-Amado
- Université de Paris, Functional and Adaptive Biology Unit, UMR (Unite Mixte de Recherche) 8251, CNRS (Centre National de la Recherche Scientifique), Paris, France
| | - Maud Soty
- Institut National de la Santé et de la Recherche Médicale, Lyon, France.,Université de Lyon, Lyon, France.,Université Lyon I, Villeurbanne, France
| | - Erwann Philippe
- Université de Paris, Functional and Adaptive Biology Unit, UMR (Unite Mixte de Recherche) 8251, CNRS (Centre National de la Recherche Scientifique), Paris, France
| | - Amelie Lacombe
- Université de Paris, Functional and Adaptive Biology Unit, UMR (Unite Mixte de Recherche) 8251, CNRS (Centre National de la Recherche Scientifique), Paris, France
| | - Julien Castel
- Université de Paris, Functional and Adaptive Biology Unit, UMR (Unite Mixte de Recherche) 8251, CNRS (Centre National de la Recherche Scientifique), Paris, France
| | - Bruno Pillot
- Institut National de la Santé et de la Recherche Médicale, Lyon, France.,Université de Lyon, Lyon, France.,Université Lyon I, Villeurbanne, France
| | - Justine Vily-Petit
- Institut National de la Santé et de la Recherche Médicale, Lyon, France.,Université de Lyon, Lyon, France.,Université Lyon I, Villeurbanne, France
| | - Carine Zitoun
- Institut National de la Santé et de la Recherche Médicale, Lyon, France.,Université de Lyon, Lyon, France.,Université Lyon I, Villeurbanne, France
| | - Gilles Mithieux
- Institut National de la Santé et de la Recherche Médicale, Lyon, France.,Université de Lyon, Lyon, France.,Université Lyon I, Villeurbanne, France
| | - Christophe Magnan
- Université de Paris, Functional and Adaptive Biology Unit, UMR (Unite Mixte de Recherche) 8251, CNRS (Centre National de la Recherche Scientifique), Paris, France
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4
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Sinet F, Soty M, Zemdegs J, Guiard B, Estrada J, Malleret G, Silva M, Mithieux G, Gautier-Stein A. Dietary Fibers and Proteins Modulate Behavior via the Activation of Intestinal Gluconeogenesis. Neuroendocrinology 2021; 111:1249-1265. [PMID: 33429400 DOI: 10.1159/000514289] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 01/07/2021] [Indexed: 11/19/2022]
Abstract
INTRODUCTION Several studies have suggested that diet, especially the one enriched in microbiota-fermented fibers or fat, regulates behavior. The underlying mechanisms are currently unknown. We previously reported that certain macronutrients (fermentable fiber and protein) regulate energy homeostasis via the activation of intestinal gluconeogenesis (IGN), which generates a neural signal to the brain. We hypothesized that these nutriments might control behavior using the same gut-brain circuit. METHODS Wild-type and IGN-deficient mice were fed chow or diets enriched in protein or fiber. Changes in their behavior were assessed using suited tests. Hippocampal neurogenesis, extracellular levels of serotonin, and protein expression levels were assessed by immunofluorescence, in vivo dialysis, and Western blotting, respectively. IGN was rescued by infusing glucose into the portal vein of IGN-deficient mice. RESULTS We show here that both fiber- and protein-enriched diets exert beneficial actions on anxiety-like and depressive-like behaviors. These benefits do not occur in mice lacking IGN. Consistently, IGN-deficient mice display hallmarks of depressive-like disorders, including decreased hippocampal neurogenesis, basal hyperactivity, and deregulation of the hypothalamic-pituitary-adrenal axis, which are associated with increased expression of the precursor of corticotropin-releasing hormone in the hypothalamus and decreased expression of the glucocorticoid receptor in the hippocampus. These neurobiological alterations are corrected by portal glucose infusion mimicking IGN. CONCLUSION IGN translates nutritional information, allowing the brain to finely coordinate energy metabolism and behavior.
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Affiliation(s)
- Flore Sinet
- INSERM UMR-S1213, Université Claude Bernard Lyon 1, Université de Lyon, Lyon, France
| | - Maud Soty
- INSERM UMR-S1213, Université Claude Bernard Lyon 1, Université de Lyon, Lyon, France
| | - Juliane Zemdegs
- CRCA - UMR 5169 - Université Paul Sabatier, Toulouse, France
| | - Bruno Guiard
- CRCA - UMR 5169 - Université Paul Sabatier, Toulouse, France
| | - Judith Estrada
- INSERM UMR-S1213, Université Claude Bernard Lyon 1, Université de Lyon, Lyon, France
| | - Gaël Malleret
- Forgetting and Cortical Dynamics, Lyon Neuroscience Research Center, Université de Lyon, Lyon, France
| | - Marine Silva
- INSERM UMR-S1213, Université Claude Bernard Lyon 1, Université de Lyon, Lyon, France
| | - Gilles Mithieux
- INSERM UMR-S1213, Université Claude Bernard Lyon 1, Université de Lyon, Lyon, France
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El Shebiny AA, Elewa GM, Gouda EAG, Hashim RM. Glucose intolerance in intensive care patients: Incidence and outcome. EGYPTIAN JOURNAL OF ANAESTHESIA 2020. [DOI: 10.1080/11101849.2020.1864253] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Affiliation(s)
- Ahmed A. El Shebiny
- Anesthesia, ICU, and Pain Management, Faculty of Medicine , Ain Shams University, Cairo, Egypt
| | - Gamal M. Elewa
- Anesthesia, ICU, and Pain Management, Faculty of Medicine , Ain Shams University, Cairo, Egypt
| | | | - Reham Mustafa Hashim
- Anesthesia, ICU, and Pain Management, Faculty of Medicine , Ain Shams University, Cairo, Egypt
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6
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Abstract
High-protein meals and foods are promoted for their beneficial effects on satiety, weight loss and glucose homeostasis. However, the mechanisms involved and the long-term benefits of such diets are still debated. We here review how the characterisation of intestinal gluconeogenesis (IGN) sheds new light on the mechanisms by which protein diets exert their beneficial effects on health. The small intestine is the third organ (in addition to the liver and kidney) contributing to endogenous glucose production via gluconeogenesis. The particularity of glucose produced by the intestine is that it is detected in the portal vein and initiates a nervous signal to the hypothalamic nuclei regulating energy homeostasis. In this context, we demonstrated that protein diets initiate their satiety effects indirectly via IGN and portal glucose sensing. This induction results in the activation of brain areas involved in the regulation of food intake. The μ-opioid-antagonistic properties of protein digests, exerted in the portal vein, are a key link between IGN induction and protein-enriched diet in the control of satiety. From our results, IGN can be proposed as a mandatory link between nutrient sensing and the regulation of whole-body homeostasis. The use of specific mouse models targeting IGN should allow us to identify several metabolic functions that could be controlled by protein diets. This will lead to the characterisation of the mechanisms by which protein diets improve whole-body homeostasis. These data could be the basis of novel nutritional strategies targeting the serious metabolic consequences of both obesity and diabetes.
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Rajas F, Gautier-Stein A, Mithieux G. Glucose-6 Phosphate, A Central Hub for Liver Carbohydrate Metabolism. Metabolites 2019; 9:metabo9120282. [PMID: 31756997 PMCID: PMC6950410 DOI: 10.3390/metabo9120282] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 11/14/2019] [Accepted: 11/18/2019] [Indexed: 12/23/2022] Open
Abstract
Cells efficiently adjust their metabolism according to the abundance of nutrients and energy. The ability to switch cellular metabolism between anabolic and catabolic processes is critical for cell growth. Glucose-6 phosphate is the first intermediate of glucose metabolism and plays a central role in the energy metabolism of the liver. It acts as a hub to metabolically connect glycolysis, the pentose phosphate pathway, glycogen synthesis, de novo lipogenesis, and the hexosamine pathway. In this review, we describe the metabolic fate of glucose-6 phosphate in a healthy liver and the metabolic reprogramming occurring in two pathologies characterized by a deregulation of glucose homeostasis, namely type 2 diabetes, which is characterized by fasting hyperglycemia; and glycogen storage disease type I, where patients develop severe hypoglycemia during short fasting periods. In these two conditions, dysfunction of glucose metabolism results in non-alcoholic fatty liver disease, which may possibly lead to the development of hepatic tumors. Moreover, we also emphasize the role of the transcription factor carbohydrate response element-binding protein (ChREBP), known to link glucose and lipid metabolisms. In this regard, comparing these two metabolic diseases is a fruitful approach to better understand the key role of glucose-6 phosphate in liver metabolism in health and disease.
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Affiliation(s)
- Fabienne Rajas
- Institut National de la Santé et de la Recherche Médicale, U1213, F-69008 Lyon, France; (A.G.-S.); (G.M.)
- Université de Lyon, F-69008 Lyon, France
- Université Lyon 1, F-69622 Villeurbanne, France
- Correspondence:
| | - Amandine Gautier-Stein
- Institut National de la Santé et de la Recherche Médicale, U1213, F-69008 Lyon, France; (A.G.-S.); (G.M.)
- Université de Lyon, F-69008 Lyon, France
- Université Lyon 1, F-69622 Villeurbanne, France
| | - Gilles Mithieux
- Institut National de la Santé et de la Recherche Médicale, U1213, F-69008 Lyon, France; (A.G.-S.); (G.M.)
- Université de Lyon, F-69008 Lyon, France
- Université Lyon 1, F-69622 Villeurbanne, France
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8
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Gjorgjieva M, Mithieux G, Rajas F. Hepatic stress associated with pathologies characterized by disturbed glucose production. Cell Stress 2019; 3:86-99. [PMID: 31225503 PMCID: PMC6551742 DOI: 10.15698/cst2019.03.179] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The liver is an organ with many facets, including a role in energy production and metabolic balance, detoxification and extraordinary capacity of regeneration. Hepatic glucose production plays a crucial role in the maintenance of normal glucose levels in the organism i.e. between 0.7 to 1.1 g/l. The loss of this function leads to a rare genetic metabolic disease named glycogen storage disease type I (GSDI), characterized by severe hypoglycemia during short fasts. On the contrary, type 2 diabetes is characterized by chronic hyperglycemia, partly due to an overproduction of glucose by the liver. Indeed, diabetes is characterized by increased uptake/production of glucose by hepatocytes, leading to the activation of de novo lipogenesis and the development of a non-alcoholic fatty liver disease. In GSDI, the accumulation of glucose-6 phosphate, which cannot be hydrolyzed into glucose, leads to an increase of glycogen stores and the development of hepatic steatosis. Thus, in these pathologies, hepatocytes are subjected to cellular stress mainly induced by glucotoxicity and lipotoxicity. In this review, we have compared hepatic cellular stress induced in type 2 diabetes and GSDI, especially oxidative stress, autophagy deregulation, and ER-stress. In addition, both GSDI and diabetic patients are prone to the development of hepatocellular adenomas (HCA) that occur on a fatty liver in the absence of cirrhosis. These HCA can further acquire malignant traits and transform into hepatocellular carcinoma. This process of tumorigenesis highlights the importance of an optimal metabolic control in both GSDI and diabetic patients in order to prevent, or at least to restrain, tumorigenic activity during disturbed glucose metabolism pathologies.
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Affiliation(s)
- Monika Gjorgjieva
- Institut National de la Santé et de la Recherche Médicale, U1213, Lyon, F-69008, France.,Université de Lyon, Lyon, F-69008 France.,Université Lyon I, Villeurbanne, F-69622 France
| | - Gilles Mithieux
- Institut National de la Santé et de la Recherche Médicale, U1213, Lyon, F-69008, France.,Université de Lyon, Lyon, F-69008 France.,Université Lyon I, Villeurbanne, F-69622 France
| | - Fabienne Rajas
- Institut National de la Santé et de la Recherche Médicale, U1213, Lyon, F-69008, France.,Université de Lyon, Lyon, F-69008 France.,Université Lyon I, Villeurbanne, F-69622 France
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10
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Abstract
PURPOSE OF REVIEW The objective of this review is to critically assess the contributing role of the gut microbiota in human obesity and type 2 diabetes (T2D). RECENT FINDINGS Experiments in animal and human studies have produced growing evidence for the causality of the gut microbiome in developing obesity and T2D. The introduction of high-throughput sequencing technologies has provided novel insight into the interpersonal differences in microbiome composition and function. The intestinal microbiota is known to be associated with metabolic syndrome and related comorbidities. Associated diseases including obesity, T2D, and fatty liver disease (NAFLD/NASH) all seem to be linked to altered microbial composition; however, causality has not been proven yet. Elucidating the potential causal and personalized role of the human gut microbiota in obesity and T2D is highly prioritized.
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Affiliation(s)
- Ömrüm Aydin
- Department of Internal Medicine, MC Slotervaart, Amsterdam, The Netherlands
- Department of Internal Medicine, AMC-UVA, Amsterdam, The Netherlands
| | - Max Nieuwdorp
- Department of Internal Medicine, AMC-UVA, Amsterdam, The Netherlands
- Diabetes Center, Department of Internal Medicine, VU University Medical Center, Amsterdam, The Netherlands
- Wallenberg Laboratory, University of Gothenberg, Gothenberg, Sweden
| | - Victor Gerdes
- Department of Internal Medicine, MC Slotervaart, Amsterdam, The Netherlands.
- Department of Internal Medicine, AMC-UVA, Amsterdam, The Netherlands.
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Kaneko K, Soty M, Zitoun C, Duchampt A, Silva M, Philippe E, Gautier-Stein A, Rajas F, Mithieux G. The role of kidney in the inter-organ coordination of endogenous glucose production during fasting. Mol Metab 2018; 16:203-212. [PMID: 29960865 PMCID: PMC6157617 DOI: 10.1016/j.molmet.2018.06.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Revised: 06/04/2018] [Accepted: 06/13/2018] [Indexed: 11/15/2022] Open
Abstract
Objective The respective contributions to endogenous glucose production (EGP) of the liver, kidney and intestine vary during fasting. We previously reported that the deficiency in either hepatic or intestinal gluconeogenesis modulates the repartition of EGP via glucagon secretion (humoral factor) and gut–brain–liver axis (neural factor), respectively. Considering renal gluconeogenesis reportedly accounted for approximately 50% of EGP during fasting, we examined whether a reduction in renal gluconeogenesis could promote alterations in the repartition of EGP in this situation. Methods We studied mice whose glucose-6-phosphatase (G6Pase) catalytic subunit (G6PC) is specifically knocked down in the kidneys (K-G6pc-/- mice) during fasting. We also examined the additional effects of intestinal G6pc deletion, renal denervation and vitamin D administration on the altered glucose metabolism in K-G6pc-/- mice. Results Compared with WT mice, K-G6pc-/- mice exhibited (1) lower glycemia, (2) enhanced intestinal but not hepatic G6Pase activity, (3) enhanced hepatic glucokinase (GK encoded by Gck) activity, (4) increased hepatic glucose-6-phosphate and (5) hepatic glycogen spared from exhaustion during fasting. Increased hepatic Gck expression in the post-absorptive state could be dependent on the enhancement of insulin signal (AKT phosphorylation) in K-G6pc-/- mice. In contrast, the increase in hepatic GK activity was not observed in mice with both kidney- and intestine-knockout (KI-G6pc-/- mice). Hepatic Gck gene expression and hepatic AKT phosphorylation were reduced in KI-G6pc-/- mice. Renal denervation by capsaicin did not induce any effect on glucose metabolism in K-G6pc-/- mice. Plasma level of 1,25 (OH)2 D3, an active form of vitamin D, was decreased in K-G6pc-/- mice. Interestingly, the administration of 1,25 (OH)2 D3 prevented the enhancement of intestinal gluconeogenesis and hepatic GK activity and blocked the accumulation of hepatic glycogen otherwise observed in K-G6pc-/- mice during fasting. Conclusions A diminution in renal gluconeogenesis that is accompanied by a decrease in blood vitamin D promotes a novel repartition of EGP among glucose producing organs during fasting, featured by increased intestinal gluconeogenesis that leads to sparing glycogen stores in the liver. Our data suggest a possible involvement of a crosstalk between the kidneys and intestine (via the vitamin D system) and the intestine and liver (via a neural gut-brain axis), which might take place in the situations of deficient renal glucose production, such as chronic kidney disease. Reduced renal G6Pase activity promotes increased hepatic glycogen during fasting. Reduced renal G6Pase activity enhances intestinal but not hepatic G6Pase activity. Reduced renal G6Pase activity results in low vitamin D level. Vitamin D injection restores metabolism in mice with reduced renal G6Pase activity.
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Affiliation(s)
- Keizo Kaneko
- Institut National de la Santé et de la Recherche Médicale, U1213, Lyon, F-69008, France; Université de Lyon, Lyon, F-69008, France; Université Lyon1, Villeurbanne, F-69622, France.
| | - Maud Soty
- Institut National de la Santé et de la Recherche Médicale, U1213, Lyon, F-69008, France; Université de Lyon, Lyon, F-69008, France; Université Lyon1, Villeurbanne, F-69622, France
| | - Carine Zitoun
- Institut National de la Santé et de la Recherche Médicale, U1213, Lyon, F-69008, France; Université de Lyon, Lyon, F-69008, France; Université Lyon1, Villeurbanne, F-69622, France
| | - Adeline Duchampt
- Institut National de la Santé et de la Recherche Médicale, U1213, Lyon, F-69008, France; Université de Lyon, Lyon, F-69008, France; Université Lyon1, Villeurbanne, F-69622, France
| | - Marine Silva
- Institut National de la Santé et de la Recherche Médicale, U1213, Lyon, F-69008, France; Université de Lyon, Lyon, F-69008, France; Université Lyon1, Villeurbanne, F-69622, France
| | - Erwann Philippe
- Institut National de la Santé et de la Recherche Médicale, U1213, Lyon, F-69008, France; Université de Lyon, Lyon, F-69008, France; Université Lyon1, Villeurbanne, F-69622, France
| | - Amandine Gautier-Stein
- Institut National de la Santé et de la Recherche Médicale, U1213, Lyon, F-69008, France; Université de Lyon, Lyon, F-69008, France; Université Lyon1, Villeurbanne, F-69622, France
| | - Fabienne Rajas
- Institut National de la Santé et de la Recherche Médicale, U1213, Lyon, F-69008, France; Université de Lyon, Lyon, F-69008, France; Université Lyon1, Villeurbanne, F-69622, France
| | - Gilles Mithieux
- Institut National de la Santé et de la Recherche Médicale, U1213, Lyon, F-69008, France; Université de Lyon, Lyon, F-69008, France; Université Lyon1, Villeurbanne, F-69622, France.
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12
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Physiological and therapeutic regulation of glucose homeostasis by upper small intestinal PepT1-mediated protein sensing. Nat Commun 2018; 9:1118. [PMID: 29549253 PMCID: PMC5856761 DOI: 10.1038/s41467-018-03490-8] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Accepted: 02/16/2018] [Indexed: 02/07/2023] Open
Abstract
High protein feeding improves glucose homeostasis in rodents and humans with diabetes, but the mechanisms that underlie this improvement remain elusive. Here we show that acute administration of casein hydrolysate directly into the upper small intestine increases glucose tolerance and inhibits glucose production in rats, independently of changes in plasma amino acids, insulin levels, and food intake. Inhibition of upper small intestinal peptide transporter 1 (PepT1), the primary oligopeptide transporter in the small intestine, reverses the preabsorptive ability of upper small intestinal casein infusion to increase glucose tolerance and suppress glucose production. The glucoregulatory role of PepT1 in the upper small intestine of healthy rats is further demonstrated by glucose homeostasis disruption following high protein feeding when PepT1 is inhibited. PepT1-mediated protein-sensing mechanisms also improve glucose homeostasis in models of early-onset insulin resistance and obesity. We demonstrate that preabsorptive upper small intestinal protein-sensing mechanisms mediated by PepT1 have beneficial effects on whole-body glucose homeostasis. High protein diets are known to improve metabolic parameters including adiposity and glucose homeostasis. Here the authors demonstrate that preabsorptive upper small intestinal protein-sensing mechanisms mediated by peptide transporter 1 improve glucose homeostasis by inhibiting hepatic glucose production.
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13
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Kavadi PK, Pothuraju R, Chagalamarri J, Bhakri G, Mallepogu A, Sharma RK. Dietary incorporation of whey protein isolate and galactooligosaccharides exhibits improvement in glucose homeostasis and insulin resistance in high fat diet fed mice. JOURNAL OF COMPLEMENTARY MEDICINE RESEARCH 2017; 6:326-332. [PMID: 28894632 PMCID: PMC5580959 DOI: 10.5455/jice.20170526091235] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Accepted: 04/23/2017] [Indexed: 12/16/2022]
Abstract
Background: This study was planned to investigate the effectiveness of the whey protein isolate (WPI) of high purity and a galactooligosaccharides (GOS) preparation on glucose homeostasis and insulin resistance in high fat diet (HFD) (45.47% energy from fat) fed conditions in C57BL/6J mice. Methods: Fasting blood glucose level, serum insulin, and glucagon-like peptide-1 (enzyme-linked immunosorbent assay) were measured; also, homeostasis model assessment of insulin resistance (HOMA-IR) was determined in different treatment groups. mRNA expression of gluconeogenesis genes in liver and small intestine tissues was analyzed by quantitative real time-polymerase chain reaction. Results: Dietary incorporation of WPI and GOS was observed to significantly resist (P < 0.001) the HFD-induced increase in blood glucose levels indicating a mitigating effect on glycemic load. It is important to note that no additive effects of administration of WPI and GOS could be observed. The administration of WPI and GOS exhibited maximum resistance (37.8%) to the rise in insulin level. Thus, the resistance to the increase in HOMA-IR was also noticed on the dietary incorporation of two functional ingredients . The positive effects on mRNA expression of phosphoenolpyruvate carboxykinase and glucose 6-phosphatase could be detected in liver only. Conclusion: Both types of functional components exhibit potential to improve glucose homeostasis under HFD fed conditions. Resistance to HFD-induced hyperinsulinemia and HOMA-IR is also recorded .
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Affiliation(s)
- Praveen Kumar Kavadi
- Department of Animal Biochemistry, National Dairy Research Institute, Karnal, Haryana, India
| | - Ramesh Pothuraju
- Department of Animal Biochemistry, National Dairy Research Institute, Karnal, Haryana, India
| | - Jayasimha Chagalamarri
- Department of Animal Biochemistry, National Dairy Research Institute, Karnal, Haryana, India
| | - Gaurav Bhakri
- Department of Animal Biochemistry, National Dairy Research Institute, Karnal, Haryana, India
| | - Aswani Mallepogu
- Department of Animal Biochemistry, National Dairy Research Institute, Karnal, Haryana, India
| | - Raj Kumar Sharma
- Department of Animal Biochemistry, National Dairy Research Institute, Karnal, Haryana, India
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14
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Abstract
Intestinal gluconeogenesis is a recently identified function influencing energy homeostasis. Intestinal gluconeogenesis induced by specific nutrients releases glucose, which is sensed by the nervous system surrounding the portal vein. This initiates a signal positively influencing parameters involved in glucose control and energy management controlled by the brain. This knowledge has extended our vision of the gut-brain axis, classically ascribed to gastrointestinal hormones. Our work raises several questions relating to the conditions under which intestinal gluconeogenesis proceeds and may provide its metabolic benefits. It also leads to questions on the advantage conferred by its conservation through a process of natural selection.
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Affiliation(s)
- Maud Soty
- Institut National de la Santé et de la Recherche Médicale, U1213, Lyon 69372, France; Université de Lyon, Lyon 69008, France; Université Lyon I, Villeurbanne 69622, France
| | - Amandine Gautier-Stein
- Institut National de la Santé et de la Recherche Médicale, U1213, Lyon 69372, France; Université de Lyon, Lyon 69008, France; Université Lyon I, Villeurbanne 69622, France
| | - Fabienne Rajas
- Institut National de la Santé et de la Recherche Médicale, U1213, Lyon 69372, France; Université de Lyon, Lyon 69008, France; Université Lyon I, Villeurbanne 69622, France
| | - Gilles Mithieux
- Institut National de la Santé et de la Recherche Médicale, U1213, Lyon 69372, France; Université de Lyon, Lyon 69008, France; Université Lyon I, Villeurbanne 69622, France.
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Absence of Role of Dietary Protein Sensing in the Metabolic Benefits of Duodenal-Jejunal Bypass in the Mouse. Sci Rep 2017; 7:44856. [PMID: 28332577 PMCID: PMC5362960 DOI: 10.1038/srep44856] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Accepted: 02/14/2017] [Indexed: 02/04/2023] Open
Abstract
Roux-en-Y gastric bypass (RYGB) induces remission or substantial improvement of type 2 diabetes mellitus (T2D) but underlying mechanisms are still unclear. The beneficial effects of dietary proteins on energy and glucose homeostasis are mediated by the antagonist effects of peptides toward mu-opioid receptors (MORs), which are highly expressed in the distal gut. We hypothesized that the beneficial effects of RYGB could depend at least in part on the interaction of peptides from food with intestinal MORs. Duodenal-jejunal bypass (DJB) was performed in obese and lean wild-type (WT) or MOR deficient (MOR−/−) mice. Food intake and body weight was monitored daily during 3 weeks. Glucose homeostasis was assessed from glucose and insulin tolerance tests. In obese WT and MOR−/− mice, DJB induced a rapid and sustained weight loss partly independent of food intake, and a rapid improvement in glycaemic parameters. Weight loss was a major determinant of the improvements observed. In lean WT and MOR−/− mice, DJB had no effect on weight loss but significantly enhanced glucose tolerance. We found that MORs are not essential in the metabolic beneficial effects of DJB, suggesting that protein sensing in the distal gut is not a link in the metabolic benefits of gastric surgery.
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Rios-Covian D, Salazar N, Gueimonde M, de Los Reyes-Gavilan CG. Shaping the Metabolism of Intestinal Bacteroides Population through Diet to Improve Human Health. Front Microbiol 2017; 8:376. [PMID: 28326076 PMCID: PMC5339271 DOI: 10.3389/fmicb.2017.00376] [Citation(s) in RCA: 130] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Accepted: 02/23/2017] [Indexed: 12/20/2022] Open
Affiliation(s)
- David Rios-Covian
- Department of Microbiology and Biochemistry of Dairy Products, Instituto de Productos Lácteos de Asturias, Consejo Superior de Investigaciones Científicas (IPLA-CSIC) Villaviciosa, Asturias, Spain
| | - Nuria Salazar
- Department of Microbiology and Biochemistry of Dairy Products, Instituto de Productos Lácteos de Asturias, Consejo Superior de Investigaciones Científicas (IPLA-CSIC) Villaviciosa, Asturias, Spain
| | - Miguel Gueimonde
- Department of Microbiology and Biochemistry of Dairy Products, Instituto de Productos Lácteos de Asturias, Consejo Superior de Investigaciones Científicas (IPLA-CSIC) Villaviciosa, Asturias, Spain
| | - Clara G de Los Reyes-Gavilan
- Department of Microbiology and Biochemistry of Dairy Products, Instituto de Productos Lácteos de Asturias, Consejo Superior de Investigaciones Científicas (IPLA-CSIC) Villaviciosa, Asturias, Spain
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Abstract
OBJECTIVE To evaluate the role of bile routing modification on the beneficial effects of gastric bypass surgery on glucose and energy metabolism. BACKGROUND Gastric bypass surgery (GBP) promotes early improvements in glucose and energy homeostasis in obese diabetic patients. A suggested mechanism associates a decrease in hepatic glucose production to an enhanced intestinal gluconeogenesis. Moreover, plasma bile acids are elevated after GBP and bile acids are inhibitors of gluconeogenesis. METHODS In male Sprague-Dawley rats, we performed bile diversions from the bile duct to the midjejunum or the mid-ileum to match the modified bile delivery in the gut occurring in GBP. Body weight, food intake, glucose tolerance, insulin sensitivity, and food preference were analyzed. The expression of gluconeogenesis genes was evaluated in both the liver and the intestine. RESULTS Bile diversions mimicking GBP promote an increase in plasma bile acids and a marked improvement in glucose control. Bile bioavailability modification is causal because a bile acid sequestrant suppresses the beneficial effects of bile diversions on glucose control. In agreement with the inhibitory role of bile acids on gluconeogenesis, bile diversions promote a blunting in hepatic glucose production, whereas intestinal gluconeogenesis is increased in the gut segments devoid of bile. In rats fed a high-fat-high-sucrose diet, bile diversions improve glucose control and dramatically decrease food intake because of an acquired disinterest in fatty food. CONCLUSIONS This study shows that bile routing modification is a key mechanistic feature in the beneficial outcomes of GBP.
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Chin SH, Item F, Wueest S, Zhou Z, Wiedemann MSF, Gai Z, Schoenle EJ, Kullak-Ublick GA, Al-Hasani H, Konrad D. Opposing effects of reduced kidney mass on liver and skeletal muscle insulin sensitivity in obese mice. Diabetes 2015; 64:1131-41. [PMID: 25325737 DOI: 10.2337/db14-0779] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Reduced kidney mass and/or function may result in multiple metabolic derangements, including insulin resistance. However, underlying mechanisms are poorly understood. Herein, we aimed to determine the impact of reduced kidney mass on glucose metabolism in lean and obese mice. To that end, 7-week-old C57BL/6J mice underwent uninephrectomy (UniNx) or sham operation. After surgery, animals were fed either a chow (standard) diet or a high-fat diet (HFD), and glucose homeostasis was assessed 20 weeks after surgery. Intraperitoneal glucose tolerance was similar in sham-operated and UniNx mice. However, insulin-stimulated glucose disposal in vivo was significantly diminished in UniNx mice, whereas insulin-stimulated glucose uptake into isolated skeletal muscle was similar in sham-operated and UniNx mice. Of note, capillary density was significantly reduced in skeletal muscle of HFD-fed UniNx mice. In contrast, hepatic insulin sensitivity was improved in UniNx mice. Furthermore, adipose tissue hypoxia-inducible factor 1α expression and inflammation were reduced in HFD-fed UniNx mice. Treatment with the angiotensin II receptor blocker telmisartan improved glucose tolerance and hepatic insulin sensitivity in HFD-fed sham-operated but not UniNx mice. In conclusion, UniNx protects from obesity-induced adipose tissue inflammation and hepatic insulin resistance, but it reduces muscle capillary density and, thus, deteriorates HFD-induced skeletal muscle glucose disposal.
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Affiliation(s)
- Siew Hung Chin
- Division of Pediatric Endocrinology and Diabetology, University Children's Hospital, Zurich, Switzerland Children's Research Center, University Children's Hospital, Zurich, Switzerland Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - Flurin Item
- Division of Pediatric Endocrinology and Diabetology, University Children's Hospital, Zurich, Switzerland Children's Research Center, University Children's Hospital, Zurich, Switzerland
| | - Stephan Wueest
- Division of Pediatric Endocrinology and Diabetology, University Children's Hospital, Zurich, Switzerland Children's Research Center, University Children's Hospital, Zurich, Switzerland
| | - Zhou Zhou
- German Diabetes Center at Heinrich Heine University, Düsseldorf, Germany
| | - Michael S F Wiedemann
- Division of Pediatric Endocrinology and Diabetology, University Children's Hospital, Zurich, Switzerland Children's Research Center, University Children's Hospital, Zurich, Switzerland Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - Zhibo Gai
- Department of Clinical Pharmacology and Toxicology, University Hospital Zurich, Zurich, Switzerland
| | - Eugen J Schoenle
- Division of Pediatric Endocrinology and Diabetology, University Children's Hospital, Zurich, Switzerland Children's Research Center, University Children's Hospital, Zurich, Switzerland
| | - Gerd A Kullak-Ublick
- Department of Clinical Pharmacology and Toxicology, University Hospital Zurich, Zurich, Switzerland
| | - Hadi Al-Hasani
- German Diabetes Center at Heinrich Heine University, Düsseldorf, Germany German Center for Diabetes Research, Düsseldorf, Germany
| | - Daniel Konrad
- Division of Pediatric Endocrinology and Diabetology, University Children's Hospital, Zurich, Switzerland Children's Research Center, University Children's Hospital, Zurich, Switzerland Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
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19
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De Vadder F, Mithieux G. Contrôle de la glycémie par l’axe nerveux intestin-cerveau. Med Sci (Paris) 2015; 31:168-73. [DOI: 10.1051/medsci/20153102013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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20
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Clar J, Mutel E, Gri B, Creneguy A, Stefanutti A, Gaillard S, Ferry N, Beuf O, Mithieux G, Nguyen TH, Rajas F. Hepatic lentiviral gene transfer prevents the long-term onset of hepatic tumours of glycogen storage disease type 1a in mice. Hum Mol Genet 2015; 24:2287-96. [DOI: 10.1093/hmg/ddu746] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
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21
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Soty M, Penhoat A, Amigo-Correig M, Vinera J, Sardella A, Vullin-Bouilloux F, Zitoun C, Houberdon I, Mithieux G. A gut-brain neural circuit controlled by intestinal gluconeogenesis is crucial in metabolic health. Mol Metab 2014; 4:106-17. [PMID: 25685698 PMCID: PMC4314540 DOI: 10.1016/j.molmet.2014.12.009] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Revised: 12/17/2014] [Accepted: 12/18/2014] [Indexed: 12/19/2022] Open
Abstract
Objectives Certain nutrients positively regulate energy homeostasis via intestinal gluconeogenesis (IGN). The objective of this study was to evaluate the impact of a deficient IGN in glucose control independently of nutritional environment. Methods We used mice deficient in the intestine glucose-6 phosphatase catalytic unit, the key enzyme of IGN (I-G6pc−/− mice). We evaluated a number of parameters involved in energy homeostasis, including insulin sensitivity (hyperinsulinemic euglycaemic clamp), the pancreatic function (insulin secretion in vivo and in isolated islets) and the hypothalamic homeostatic function (leptin sensitivity). Results Intestinal-G6pc−/− mice exhibit slight fasting hyperglycaemia and hyperinsulinemia, glucose intolerance, insulin resistance and a deteriorated pancreatic function, despite normal diet with no change in body weight. These defects evoking type 2 diabetes (T2D) derive from the basal activation of the sympathetic nervous system (SNS). They are corrected by treatment with an inhibitor of α-2 adrenergic receptors. Deregulation in a key target of IGN, the homeostatic hypothalamic function (highlighted here through leptin resistance) is a mechanistic link. Hence the leptin resistance and metabolic disorders in I-G6pc−/− mice are corrected by rescuing IGN by portal glucose infusion. Finally, I-G6pc−/− mice develop the hyperglycaemia characteristic of T2D more rapidly under high fat/high sucrose diet. Conclusions Intestinal gluconeogenesis is a mandatory function for the healthy neural control of glucose homeostasis.
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Affiliation(s)
- Maud Soty
- Institut National de la Santé et de la Recherche Médicale, U855, Lyon, F-69008, France
- Université de Lyon, Lyon, F-69008, France
- Université Lyon1, Villeurbanne, F-69622, France
| | - Armelle Penhoat
- Institut National de la Santé et de la Recherche Médicale, U855, Lyon, F-69008, France
- Université de Lyon, Lyon, F-69008, France
- Université Lyon1, Villeurbanne, F-69622, France
| | - Marta Amigo-Correig
- Institut National de la Santé et de la Recherche Médicale, U855, Lyon, F-69008, France
- Université de Lyon, Lyon, F-69008, France
- Université Lyon1, Villeurbanne, F-69622, France
| | - Jennifer Vinera
- Institut National de la Santé et de la Recherche Médicale, U855, Lyon, F-69008, France
- Université de Lyon, Lyon, F-69008, France
- Université Lyon1, Villeurbanne, F-69622, France
| | - Anne Sardella
- Institut National de la Santé et de la Recherche Médicale, U855, Lyon, F-69008, France
- Université de Lyon, Lyon, F-69008, France
- Université Lyon1, Villeurbanne, F-69622, France
| | - Fanny Vullin-Bouilloux
- Institut National de la Santé et de la Recherche Médicale, U855, Lyon, F-69008, France
- Université de Lyon, Lyon, F-69008, France
- Université Lyon1, Villeurbanne, F-69622, France
| | - Carine Zitoun
- Institut National de la Santé et de la Recherche Médicale, U855, Lyon, F-69008, France
- Université de Lyon, Lyon, F-69008, France
- Université Lyon1, Villeurbanne, F-69622, France
| | - Isabelle Houberdon
- Institut National de la Santé et de la Recherche Médicale, U855, Lyon, F-69008, France
- Université de Lyon, Lyon, F-69008, France
- Université Lyon1, Villeurbanne, F-69622, France
| | - Gilles Mithieux
- Institut National de la Santé et de la Recherche Médicale, U855, Lyon, F-69008, France
- Université de Lyon, Lyon, F-69008, France
- Université Lyon1, Villeurbanne, F-69622, France
- Corresponding author. Inserm U855, Faculté de Médecine Laennec, 7 rue Guillaume Paradin, 69372, Lyon cedex 08, France. Tel.: +33 478 77 10 28; fax: +33 478 77 87 62.
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22
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Abdul-Wahed A, Gautier-Stein A, Casteras S, Soty M, Roussel D, Romestaing C, Guillou H, Tourette JA, Pleche N, Zitoun C, Gri B, Sardella A, Rajas F, Mithieux G. A link between hepatic glucose production and peripheral energy metabolism via hepatokines. Mol Metab 2014; 3:531-43. [PMID: 25061558 PMCID: PMC4099510 DOI: 10.1016/j.molmet.2014.05.005] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Revised: 05/16/2014] [Accepted: 05/20/2014] [Indexed: 12/25/2022] Open
Abstract
Type 2 diabetes is characterized by a deterioration of glucose tolerance, which associates insulin resistance of glucose uptake by peripheral tissues and increased endogenous glucose production. Here we report that the specific suppression of hepatic glucose production positively modulates whole-body glucose and energy metabolism. We used mice deficient in liver glucose-6 phosphatase that is mandatory for endogenous glucose production. When they were fed a high fat/high sucrose diet, they resisted the development of diabetes and obesity due to the activation of peripheral glucose metabolism and thermogenesis. This was linked to the secretion of hepatic hormones like fibroblast growth factor 21 and angiopoietin-like factor 6. Interestingly, the deletion of hepatic glucose-6 phosphatase in previously obese and insulin-resistant mice resulted in the rapid restoration of glucose and body weight controls. Therefore, hepatic glucose production is an essential lever for the control of whole-body energy metabolism during the development of obesity and diabetes.
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Affiliation(s)
- Aya Abdul-Wahed
- Institut National de la Santé et de la Recherche Médicale, U855, Lyon, F-69008, France ; Université de Lyon, Lyon, F-69008, France ; Université Lyon 1, Villeurbanne, F-69622, France ; University of Aleppo, Aleppo, Syria
| | - Amandine Gautier-Stein
- Institut National de la Santé et de la Recherche Médicale, U855, Lyon, F-69008, France ; Université de Lyon, Lyon, F-69008, France ; Université Lyon 1, Villeurbanne, F-69622, France
| | - Sylvie Casteras
- Institut National de la Santé et de la Recherche Médicale, U855, Lyon, F-69008, France ; Université de Lyon, Lyon, F-69008, France ; Université Lyon 1, Villeurbanne, F-69622, France
| | - Maud Soty
- Institut National de la Santé et de la Recherche Médicale, U855, Lyon, F-69008, France ; Université de Lyon, Lyon, F-69008, France ; Université Lyon 1, Villeurbanne, F-69622, France
| | - Damien Roussel
- Université de Lyon, Lyon, F-69008, France ; Université Lyon 1, Villeurbanne, F-69622, France ; Centre National de la Recherche Scientifique, UMR5023, Villeurbanne, F-69622, France
| | - Caroline Romestaing
- Université de Lyon, Lyon, F-69008, France ; Université Lyon 1, Villeurbanne, F-69622, France ; Centre National de la Recherche Scientifique, UMR5023, Villeurbanne, F-69622, France
| | | | - Jean-André Tourette
- Institut National de la Santé et de la Recherche Médicale, U855, Lyon, F-69008, France ; Université de Lyon, Lyon, F-69008, France ; Université Lyon 1, Villeurbanne, F-69622, France
| | - Nicolas Pleche
- Institut National de la Santé et de la Recherche Médicale, U855, Lyon, F-69008, France ; Université de Lyon, Lyon, F-69008, France ; Université Lyon 1, Villeurbanne, F-69622, France
| | - Carine Zitoun
- Institut National de la Santé et de la Recherche Médicale, U855, Lyon, F-69008, France ; Université de Lyon, Lyon, F-69008, France ; Université Lyon 1, Villeurbanne, F-69622, France
| | - Blandine Gri
- Institut National de la Santé et de la Recherche Médicale, U855, Lyon, F-69008, France ; Université de Lyon, Lyon, F-69008, France ; Université Lyon 1, Villeurbanne, F-69622, France
| | - Anne Sardella
- Institut National de la Santé et de la Recherche Médicale, U855, Lyon, F-69008, France ; Université de Lyon, Lyon, F-69008, France ; Université Lyon 1, Villeurbanne, F-69622, France
| | - Fabienne Rajas
- Institut National de la Santé et de la Recherche Médicale, U855, Lyon, F-69008, France ; Université de Lyon, Lyon, F-69008, France ; Université Lyon 1, Villeurbanne, F-69622, France
| | - Gilles Mithieux
- Institut National de la Santé et de la Recherche Médicale, U855, Lyon, F-69008, France ; Université de Lyon, Lyon, F-69008, France ; Université Lyon 1, Villeurbanne, F-69622, France
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23
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De Vadder F, Mithieux G. Les fibres alimentaires induisent des bénéfices métaboliques via l’activation de la néoglucogenèse intestinale. ACTA ACUST UNITED AC 2014. [DOI: 10.1007/s11690-014-0451-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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24
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Clar J, Gri B, Calderaro J, Birling MC, Hérault Y, Smit GPA, Mithieux G, Rajas F. Targeted deletion of kidney glucose-6 phosphatase leads to nephropathy. Kidney Int 2014; 86:747-56. [PMID: 24717294 DOI: 10.1038/ki.2014.102] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Revised: 01/27/2014] [Accepted: 02/13/2014] [Indexed: 12/18/2022]
Abstract
Renal failure is a major complication that arises with aging in glycogen storage disease type 1a and type 1b patients. In the kidneys, glucose-6 phosphatase catalytic subunit (encoded by G6pc) deficiency leads to the accumulation of glycogen, an effect resulting in marked nephromegaly and progressive glomerular hyperperfusion and hyperfiltration preceding the development of microalbuminuria and proteinuria. To better understand the end-stage nephropathy in glycogen storage disease type 1a, we generated a novel kidney-specific G6pc knockout (K-G6pc(-/-)) mouse, which exhibited normal life expectancy. After 6 months, K-G6pc(-/-) mice showed glycogen overload leading to nephromegaly and tubular dilation. Moreover, renal accumulation of lipids due to activation of de novo lipogenesis was observed. This led to the activation of the renin-angiotensin system and the development of epithelial-mesenchymal transition process and podocyte injury by transforming growth factor β1 signaling. The K-G6pc(-/-) mice developed microalbuminuria caused by the impairment of the glomerular filtration barrier. Thus, renal G6pc deficiency alone is sufficient to induce the development of the early-onset nephropathy observed in glycogen storage disease type 1a, independent of the liver disease. The K-G6pc(-/-) mouse model is a unique tool to decipher the molecular mechanisms underlying renal failure and to evaluate potential therapeutic strategies.
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Affiliation(s)
- Julie Clar
- 1] Institut National de la Santé et de la Recherche Médicale, U855, Lyon, France [2] Université de Lyon, Lyon, France [3] Université Lyon 1, Villeurbanne, France
| | - Blandine Gri
- 1] Institut National de la Santé et de la Recherche Médicale, U855, Lyon, France [2] Université de Lyon, Lyon, France [3] Université Lyon 1, Villeurbanne, France
| | - Julien Calderaro
- Département de Pathologie, Hôpital Henri Mondor, Créteil, France
| | - Marie-Christine Birling
- Institut Clinique de la Souris, Phenomin IGBMC, CNRS, Université de Strasbourg INSERM, U964, Illkirch, France
| | - Yann Hérault
- Institut Clinique de la Souris, Phenomin IGBMC, CNRS, Université de Strasbourg INSERM, U964, Illkirch, France
| | - G Peter A Smit
- Universitair Medisch Centrum Groningen, Groningen, The Netherlands
| | - Gilles Mithieux
- 1] Institut National de la Santé et de la Recherche Médicale, U855, Lyon, France [2] Université de Lyon, Lyon, France [3] Université Lyon 1, Villeurbanne, France
| | - Fabienne Rajas
- 1] Institut National de la Santé et de la Recherche Médicale, U855, Lyon, France [2] Université de Lyon, Lyon, France [3] Université Lyon 1, Villeurbanne, France
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25
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De Vadder F, Kovatcheva-Datchary P, Goncalves D, Vinera J, Zitoun C, Duchampt A, Bäckhed F, Mithieux G. Microbiota-generated metabolites promote metabolic benefits via gut-brain neural circuits. Cell 2014; 156:84-96. [PMID: 24412651 DOI: 10.1016/j.cell.2013.12.016] [Citation(s) in RCA: 1483] [Impact Index Per Article: 148.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Revised: 10/15/2013] [Accepted: 12/11/2013] [Indexed: 12/22/2022]
Abstract
Soluble dietary fibers promote metabolic benefits on body weight and glucose control, but underlying mechanisms are poorly understood. Recent evidence indicates that intestinal gluconeogenesis (IGN) has beneficial effects on glucose and energy homeostasis. Here, we show that the short-chain fatty acids (SCFAs) propionate and butyrate, which are generated by fermentation of soluble fiber by the gut microbiota, activate IGN via complementary mechanisms. Butyrate activates IGN gene expression through a cAMP-dependent mechanism, while propionate, itself a substrate of IGN, activates IGN gene expression via a gut-brain neural circuit involving the fatty acid receptor FFAR3. The metabolic benefits on body weight and glucose control induced by SCFAs or dietary fiber in normal mice are absent in mice deficient for IGN, despite similar modifications in gut microbiota composition. Thus, the regulation of IGN is necessary for the metabolic benefits associated with SCFAs and soluble fiber.
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Affiliation(s)
- Filipe De Vadder
- Institut de la Santé et de la Recherche Médicale, U855, Lyon 69372, France; Université de Lyon, Lyon 69008, France; Université Lyon 1, Villeurbanne 69622, France
| | - Petia Kovatcheva-Datchary
- Wallenberg Laboratory and Department of Molecular and Clinical Medicine, University of Gothenburg 41345, Sweden
| | - Daisy Goncalves
- Institut de la Santé et de la Recherche Médicale, U855, Lyon 69372, France; Université de Lyon, Lyon 69008, France; Université Lyon 1, Villeurbanne 69622, France
| | - Jennifer Vinera
- Institut de la Santé et de la Recherche Médicale, U855, Lyon 69372, France; Université de Lyon, Lyon 69008, France; Université Lyon 1, Villeurbanne 69622, France
| | - Carine Zitoun
- Institut de la Santé et de la Recherche Médicale, U855, Lyon 69372, France; Université de Lyon, Lyon 69008, France; Université Lyon 1, Villeurbanne 69622, France
| | - Adeline Duchampt
- Institut de la Santé et de la Recherche Médicale, U855, Lyon 69372, France; Université de Lyon, Lyon 69008, France; Université Lyon 1, Villeurbanne 69622, France
| | - Fredrik Bäckhed
- Wallenberg Laboratory and Department of Molecular and Clinical Medicine, University of Gothenburg 41345, Sweden; Novo Nordisk Foundation Center for Basic Metabolic Research, Section for Metabolic Receptology and Enteroendocrinology, Faculty of Health Sciences, University of Copenhagen, Copenhagen 2200, Denmark
| | - Gilles Mithieux
- Institut de la Santé et de la Recherche Médicale, U855, Lyon 69372, France; Université de Lyon, Lyon 69008, France; Université Lyon 1, Villeurbanne 69622, France.
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26
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Penhoat A, Fayard L, Stefanutti A, Mithieux G, Rajas F. Intestinal gluconeogenesis is crucial to maintain a physiological fasting glycemia in the absence of hepatic glucose production in mice. Metabolism 2014; 63:104-11. [PMID: 24135501 DOI: 10.1016/j.metabol.2013.09.005] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2013] [Revised: 09/08/2013] [Accepted: 09/09/2013] [Indexed: 11/20/2022]
Abstract
OBJECTIVE Similar to the liver and kidneys, the intestine has been strongly suggested to be a gluconeogenic organ. However, the precise contribution of the intestine to endogenous glucose production (EGP) remains to be determined. To define the quantitative role of intestinal gluconeogenesis during long-term fasting, we compared changes in blood glucose during prolonged fasting in mice with a liver-deletion of the glucose-6 phosphatase catalytic (G6PC) subunit (LKO) and in mice with a combined deletion of G6PC in both the liver and the intestine (ILKO). MATERIALS/METHODS The LKO and ILKO mice were studied after 6h and 40 h of fasting by measuring metabolic and hormonal plasmatic parameters, as well as the expression of gluconeogenic enzymes in the liver, kidneys and intestine. RESULTS After a transient hypoglycemic episode (approximately 60 mg/dL) because of their incapacity to mobilize liver glycogen, the LKO mice progressively re-increased their plasma glucose to reach a glycemia comparable to that of wild-type mice (90 mg/dL) from 30 h of fasting. This increase was associated with a rapid induction of renal and intestinal gluconeogenic gene expression, driven by glucagon, glucocorticoids and acidosis. The ILKO mice exhibited a similar induction of renal gluconeogenesis. However, these mice failed to re-increase their glycemia and maintained a plasma glucose level of only 60 mg/dL throughout the 48 h-fasting period. CONCLUSIONS These data indicate that intestinal glucose production is essential to maintain glucose homeostasis in the absence of hepatic glucose production during fasting. These data provide a definitive quantitative estimate of the capacity of intestinal gluconeogenesis to sustain EGP during long-term fasting.
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Affiliation(s)
- Armelle Penhoat
- Institut National de la Santé et de la Recherche Médicale, U855, Lyon 69372, France; University of Lyon, Lyon 69008, France; University Lyon 1, Villeurbanne 69622, France
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Saraswathi V, Ramnanan CJ, Wilks AW, Desouza CV, Eller AA, Murali G, Ramalingam R, Milne GL, Coate KC, Edgerton DS. Impact of hematopoietic cyclooxygenase-1 deficiency on obesity-linked adipose tissue inflammation and metabolic disorders in mice. Metabolism 2013; 62:1673-85. [PMID: 23987235 PMCID: PMC4845736 DOI: 10.1016/j.metabol.2013.07.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2013] [Revised: 06/13/2013] [Accepted: 07/16/2013] [Indexed: 01/21/2023]
Abstract
OBJECTIVE Adipose tissue (AT)-specific inflammation is considered to mediate the pathological consequences of obesity and macrophages are known to activate inflammatory pathways in obese AT. Because cyclooxygenases play a central role in regulating the inflammatory processes, we sought to determine the role of hematopoietic cyclooxygenase-1 (COX-1) in modulating AT inflammation in obesity. MATERIALS/METHODS Bone marrow transplantation was performed to delete COX-1 in hematopoietic cells. Briefly, female wild type (wt) mice were lethally irradiated and injected with bone marrow (BM) cells collected from wild type (COX-1+/+) or COX-1 knock-out (COX-1-/-) donor mice. The mice were fed a high fat diet for 16 weeks. RESULTS The mice that received COX-1-/- bone marrow (BM-COX-1-/-) exhibited a significant increase in fasting glucose, total cholesterol and triglycerides in the circulation compared to control (BM-COX-1+/+) mice. Markers of AT-inflammation were increased and were associated with increased leptin and decreased adiponectin in plasma. Hepatic inflammation was reduced with a concomitant reduction in TXB2 levels. The hepatic mRNA expression of genes involved in lipogenesis and lipid transport was increased while expression of genes involved in regulating hepatic glucose output was reduced in BM-COX-1-/- mice. Finally, renal inflammation and markers of renal glucose release were increased in BM-COX-1-/- mice. CONCLUSION Hematopoietic COX-1 deletion results in impairments in metabolic homeostasis which may be partly due to increased AT inflammation and dysregulated adipokine profile. An increase in renal glucose release and hepatic lipogenesis/lipid transport may also play a role, at least in part, in mediating hyperglycemia and dyslipidemia, respectively.
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Affiliation(s)
- Viswanathan Saraswathi
- Department of Molecular Physiology and Biophysics; Department of Internal Medicine/Division of Diabetes, Endocrinology, and Metabolism; Department of Cellular and Integrative Physiology, University of Nebraska Medical Center; VA Nebraska Western Iowa Health Care System, Omaha, NE.
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Glycogen storage disease type 1 and diabetes: Learning by comparing and contrasting the two disorders. DIABETES & METABOLISM 2013; 39:377-87. [DOI: 10.1016/j.diabet.2013.03.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2013] [Revised: 02/25/2013] [Accepted: 03/11/2013] [Indexed: 12/18/2022]
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29
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Mithieux G. Nutrient control of hunger by extrinsic gastrointestinal neurons. Trends Endocrinol Metab 2013; 24:378-84. [PMID: 23714040 DOI: 10.1016/j.tem.2013.04.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2013] [Revised: 04/19/2013] [Accepted: 04/24/2013] [Indexed: 10/26/2022]
Abstract
The neural sensing of nutrients during food digestion plays a key role in the regulation of hunger. Recent data have emphasized that the extrinsic gastrointestinal nervous system is preponderant in this phenomenon and in its translation to the control of food intake by the central nervous system (CNS). Nutrient sensing by the extrinsic gastrointestinal nervous system may account for the satiation induced by food lipids, the satiety initiated by food protein, and for the rapid benefits of gastric bypass surgeries on both glucose and energy homeostasis. Thus, this recent knowledge provides novel examples of the mechanisms that control food intake and body weight, and this might pave the way for future approaches to the prevention and/or treatment of obesity.
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Affiliation(s)
- Gilles Mithieux
- Institut National de la Santé et de la Recherche Médicale Unité 855, Faculté de Médecine Lyon-Est 'Laennec', 69372 Lyon CEDEX 08, France.
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Gatica R, Bertinat R, Silva P, Carpio D, Ramírez MJ, Slebe JC, San Martín R, Nualart F, Campistol JM, Caelles C, Yáñez AJ. Altered expression and localization of insulin receptor in proximal tubule cells from human and rat diabetic kidney. J Cell Biochem 2013; 114:639-49. [PMID: 23059533 DOI: 10.1002/jcb.24406] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2012] [Accepted: 09/21/2012] [Indexed: 01/11/2023]
Abstract
Diabetes is the major cause of end stage renal disease, and tubular alterations are now considered to participate in the development and progression of diabetic nephropathy (DN). Here, we report for the first time that expression of the insulin receptor (IR) in human kidney is altered during diabetes. We detected a strong expression in proximal and distal tubules from human renal cortex, and a significant reduction in type 2 diabetic patients. Moreover, isolated proximal tubules from type 1 diabetic rat kidney showed a similar response, supporting its use as an excellent model for in vitro study of human DN. IR protein down-regulation was paralleled in proximal and distal tubules from diabetic rats, but prominent in proximal tubules from diabetic patients. A target of renal insulin signaling, the gluconeogenic enzyme phosphoenolpyruvate carboxykinase (PEPCK), showed increased expression and activity, and localization in compartments near the apical membrane of proximal tubules, which was correlated with activation of the GSK3β kinase in this specific renal structure in the diabetic condition. Thus, expression of IR protein in proximal tubules from type 1 and type 2 diabetic kidney indicates that this is a common regulatory mechanism which is altered in DN, triggering enhanced gluconeogenesis regardless the etiology of the disease.
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Affiliation(s)
- Rodrigo Gatica
- Instituto de Bioquímica y Microbiología, Facultad de Ciencias, Universidad Austral de Chile, Región de los Ríos, Valdivia, Chile
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31
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De Vadder F, Gautier-Stein A, Mithieux G. [Opioid receptors associated with portal vein regulate a gut-brain neural circuitry limiting food intake]. Med Sci (Paris) 2013; 29:31-3. [PMID: 23351691 DOI: 10.1051/medsci/2013291010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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32
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Delaere F, Duchampt A, Mounien L, Seyer P, Duraffourd C, Zitoun C, Thorens B, Mithieux G. The role of sodium-coupled glucose co-transporter 3 in the satiety effect of portal glucose sensing. Mol Metab 2012; 2:47-53. [PMID: 24024129 DOI: 10.1016/j.molmet.2012.11.003] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2012] [Revised: 11/27/2012] [Accepted: 11/29/2012] [Indexed: 01/12/2023] Open
Abstract
Portal vein glucose sensors detect variations in glycemia to induce a nervous signal that influences food intake and glucose homeostasis. Previous experiments using high infusions of glucose suggested a metabolic sensing involving glucose transporter 2 (GLUT2). Here we evaluated the afferent route for the signal and candidate molecules for detecting low glucose fluxes. Common hepatic branch vagotomy did not abolish the anorectic effect of portal glucose, indicating dorsal transmission. GLUT2-null mice reduced their food intake in response to portal glucose signal initiated by protein-enriched diet. A similar response of Trpm5-null mice and portal infusions of sweeteners also excluded sugar taste receptors. Conversely, infusions of alpha-methylglucose, but not 3-O-methylglucose, decreased food intake, while phlorizin prevented the effect of glucose. This suggested sensing through SGLT3, which was expressed in the portal area. From these results we propose a finely tuned dual mechanism for portal glucose sensing that responds to different physiological conditions.
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Key Words
- (3-O-MDG), 3-O-methyl-d-glucopyranose
- (5-HT), 5-hydroxytryptamin/serotonin
- (EGP), endogenous glucose production
- (G6PC), glucose-6-phosphatase catalytic subunit
- (GAPDH), glyceraldehyde-3-phosphate dehydrogenase
- (GFAP), glial fibriallary acidic protein
- (GLP1), glucagon-like peptide 1
- (GLUT), glucose transporter
- (PED), protein-enriched diet
- (PGP9.5), protein gene product 9.5
- (SED), starch-enriched diet
- (SGLT), sodium glucose co-transporter
- (Trpm5), transient receptor potential melastin 5
- (αMDG), α-methylglucopyranoside
- Food intake
- Glucose metabolism
- Glucose sensing
- Peripheral nervous signal
- Portal vein
- SGLTs
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Affiliation(s)
- Fabien Delaere
- Institut National de la Santé et de la Recherche Médicale, U 855, Lyon 69372, France ; Université de Lyon, Lyon 69008, France ; Université Lyon 1, Villeurbanne 69622, France ; AgroParisTech, ENGREF, Paris F-75732, France
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Oishi K, Uchida D, Itoh N. Low-carbohydrate, high-protein diet affects rhythmic expression of gluconeogenic regulatory and circadian clock genes in mouse peripheral tissues. Chronobiol Int 2012; 29:799-809. [PMID: 22823864 DOI: 10.3109/07420528.2012.699127] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Recent studies have demonstrated that metabolic changes in mammals induce feedback regulation of the circadian clock. The present study evaluates the effects of a low-carbohydrate high-protein diet (HPD) on circadian behavior and peripheral circadian clocks in mice. Circadian rhythms of locomotor activity and core body temperature remained normal in mice fed with the HPD diet (HPD mice), suggesting that it did not affect the central clock in the hypothalamus. Two weeks of HPD feeding induced mild hypoglycemia without affecting body weight, although these mice consumed more calories than mice fed with a normal diet (ND mice). Plasma insulin levels were increased during the inactive phase in HPD mice, but increased twice, beginning and end of the active phase, in ND mice. Expression levels of the key gluconeogenic regulatory genes PEPCK and G6Pase were significantly induced in the liver and kidneys of HPD mice. The HPD appeared to induce peroxisome proliferator-activated receptor α (PPARα) activation, since mRNA expression levels of PPARα and its typical target genes, such as PDK4 and Cyp4A10, were significantly increased in the liver and kidneys. Circadian mRNA expression of clock genes, such as BMAL1, Cry1, NPAS2, and Rev-erbα, but not Per2, was significantly phase-advanced, and mean expression levels of BMAL1 and Cry1 mRNAs were significantly elevated, in the liver and kidneys of HPD mice. These findings suggest that a HPD not only affects glucose homeostasis, but that it also advances the molecular circadian clock in peripheral tissues.
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Affiliation(s)
- Katsutaka Oishi
- Biological Clock Research Group, Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki, Japan.
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Gautier-Stein A, Soty M, Chilloux J, Zitoun C, Rajas F, Mithieux G. Glucotoxicity induces glucose-6-phosphatase catalytic unit expression by acting on the interaction of HIF-1α with CREB-binding protein. Diabetes 2012; 61:2451-60. [PMID: 22787137 PMCID: PMC3447892 DOI: 10.2337/db11-0986] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The activation of glucose-6-phosphatase (G6Pase), a key enzyme of endogenous glucose production, is correlated with type 2 diabetes. Type 2 diabetes is characterized by sustained hyperglycemia leading to glucotoxicity. We investigated whether glucotoxicity mechanisms control the expression of the G6Pase catalytic unit (G6pc). We deciphered the transcriptional regulatory mechanisms of the G6pc promoter by glucotoxicity in a hepatoma cell line then in primary hepatocytes and in the liver of diabetic mice. High glucose exposure induced the production of reactive oxygen species (ROS) and, in parallel, induced G6pc promoter activity. In hepatocytes, glucose induced G6pc gene expression and glucose release. The decrease of ROS concentrations by antioxidants eliminated all the glucose-inductive effects. The induction of G6pc promoter activity by glucose was eliminated in the presence of small interfering RNA, targeting either the hypoxia-inducible factor (HIF)-1α or the CREB-binding protein (CBP). Glucose increased the interaction of HIF-1α with CBP and the recruitment of HIF-1 on the G6pc promoter. The same mechanism might occur in hyperglycemic mice. We deciphered a new regulatory mechanism induced by glucotoxicity. This mechanism leading to the induction of HIF-1 transcriptional activity may contribute to the increase of hepatic glucose production during type 2 diabetes.
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Mithieux G. Comment about intestinal gluconeogenesis after gastric bypass in human in relation with the paper by Hayes et al., Obes. Surg. 2011. Obes Surg 2012; 22:1920-2; author reply 1923-4. [DOI: 10.1007/s11695-012-0755-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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Mu-opioid receptors and dietary protein stimulate a gut-brain neural circuitry limiting food intake. Cell 2012; 150:377-88. [PMID: 22771138 DOI: 10.1016/j.cell.2012.05.039] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2011] [Revised: 03/02/2012] [Accepted: 05/09/2012] [Indexed: 11/21/2022]
Abstract
Intestinal gluconeogenesis is involved in the control of food intake. We show that mu-opioid receptors (MORs) present in nerves in the portal vein walls respond to peptides to regulate a gut-brain neural circuit that controls intestinal gluconeogenesis and satiety. In vitro, peptides and protein digests behave as MOR antagonists in competition experiments. In vivo, they stimulate MOR-dependent induction of intestinal gluconeogenesis via activation of brain areas receiving inputs from gastrointestinal ascending nerves. MOR-knockout mice do not carry out intestinal gluconeogenesis in response to peptides and are insensitive to the satiety effect induced by protein-enriched diets. Portal infusions of MOR modulators have no effect on food intake in mice deficient for intestinal gluconeogenesis. Thus, the regulation of portal MORs by peptides triggering signals to and from the brain to induce intestinal gluconeogenesis are links in the satiety phenomenon associated with alimentary protein assimilation.
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37
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Mithieux G. A synergy between incretin effect and intestinal gluconeogenesis accounting for the rapid metabolic benefits of gastric bypass surgery. Curr Diab Rep 2012; 12:167-71. [PMID: 22311610 DOI: 10.1007/s11892-012-0257-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Abstract
The early improvement of glucose control taking place shortly after gastric bypass surgery in obese diabetic patients has long been mysterious. A recent study in mice has highlighted some specific mechanisms underlying this phenomenon. The specificity of gastric bypass in obese diabetic mice relates to major changes in the sensations of hunger and to rapid improvement of glucose parameters. The induction of intestinal gluconeogenesis plays a major role in diminishing hunger, and in restoring insulin sensitivity of endogenous glucose production. In parallel, the restoration of the secretion of glucagon-like peptide 1 and insulin plays a key additional role, in this context of recovered insulin sensitivity, to improve postprandial glucose tolerance. Therefore, a synergy between an incretin effect and intestinal gluconeogenesis is a key feature accounting for the rapid improvement of glucose control in obese diabetic patients after bypass surgery.
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38
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Naville D, Duchampt A, Vigier M, Oursel D, Lessire R, Poirier H, Niot I, Bégeot M, Besnard P, Mithieux G. Link between intestinal CD36 ligand binding and satiety induced by a high protein diet in mice. PLoS One 2012; 7:e30686. [PMID: 22295104 PMCID: PMC3266275 DOI: 10.1371/journal.pone.0030686] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2011] [Accepted: 12/21/2011] [Indexed: 01/09/2023] Open
Abstract
CD36 is a ubiquitous membrane glycoprotein that binds long-chain fatty acids. The presence of a functional CD36 is required for the induction of satiety by a lipid load and its role as a lipid receptor driving cellular signal has recently been demonstrated. Our project aimed to further explore the role of intestinal CD36 in the regulation of food intake. Duodenal infusions of vehicle or sulfo-N-succinimidyl-oleate (SSO) was performed prior to acute infusions of saline or Intralipid (IL) in mice. Infusion of minute quantities of IL induced a decrease in food intake (FI) compared to saline. Infusion of SSO had the same effect but no additive inhibitory effect was observed in presence of IL. No IL- or SSO-mediated satiety occurred in CD36-null mice. To determine whether the CD36-mediated hypophagic effect of lipids was maintained in animals fed a satietogen diet, mice were subjected to a High-Protein diet (HPD). Concomitantly with the satiety effect, a rise in intestinal CD36 gene expression was observed. No satiety effect occurred in CD36-null mice. HPD-fed WT mice showed a diminished FI compared to control mice, after saline duodenal infusion. But there was no further decrease after lipid infusion. The lipid-induced decrease in FI observed on control mice was accompanied by a rise in jejunal oleylethanolamide (OEA). Its level was higher in HPD-fed mice than in controls after saline infusion and was not changed by lipids. Overall, we demonstrate that lipid binding to intestinal CD36 is sufficient to produce a satiety effect. Moreover, it could participate in the satiety effect induced by HPD. Intestine can modulate FI by several mechanisms including an increase in OEA production and CD36 gene expression. Furthermore, intestine of mice adapted to HPD have a diminished capacity to modulate their food intake in response to dietary lipids.
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39
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Mutel E, Gautier-Stein A, Abdul-Wahed A, Amigó-Correig M, Zitoun C, Stefanutti A, Houberdon I, Tourette JA, Mithieux G, Rajas F. Control of blood glucose in the absence of hepatic glucose production during prolonged fasting in mice: induction of renal and intestinal gluconeogenesis by glucagon. Diabetes 2011; 60:3121-31. [PMID: 22013018 PMCID: PMC3219939 DOI: 10.2337/db11-0571] [Citation(s) in RCA: 128] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
OBJECTIVE Since the pioneering work of Claude Bernard, the scientific community has considered the liver to be the major source of endogenous glucose production in all postabsorptive situations. Nevertheless, the kidneys and intestine can also produce glucose in blood, particularly during fasting and under protein feeding. The aim of this study was to better define the importance of the three gluconeogenic organs in glucose homeostasis. RESEARCH DESIGN AND METHODS We investigated blood glucose regulation during fasting in a mouse model of inducible liver-specific deletion of the glucose-6-phosphatase gene (L-G6pc(-/-) mice), encoding a mandatory enzyme for glucose production. Furthermore, we characterized molecular mechanisms underlying expression changes of gluconeogenic genes (G6pc, Pck1, and glutaminase) in both the kidneys and intestine. RESULTS We show that the absence of hepatic glucose release had no major effect on the control of fasting plasma glucose concentration. Instead, compensatory induction of gluconeogenesis occurred in the kidneys and intestine, driven by glucagon, glucocorticoids, and acidosis. Moreover, the extrahepatic action of glucagon took place in wild-type mice. CONCLUSIONS Our study provides a definitive quantitative estimate of the capacity of extrahepatic gluconeogenesis to sustain fasting endogenous glucose production under the control of glucagon, regardless of the contribution of the liver. Thus, the current dogma relating to the respective role of the liver and of extrahepatic gluconeogenic organs in glucose homeostasis requires re-examination.
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Penhoat A, Mutel E, Amigo-Correig M, Pillot B, Stefanutti A, Rajas F, Mithieux G. Protein-induced satiety is abolished in the absence of intestinal gluconeogenesis. Physiol Behav 2011; 105:89-93. [DOI: 10.1016/j.physbeh.2011.03.012] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2010] [Revised: 02/21/2011] [Accepted: 03/08/2011] [Indexed: 12/26/2022]
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Waget A, Cabou C, Masseboeuf M, Cattan P, Armanet M, Karaca M, Castel J, Garret C, Payros G, Maida A, Sulpice T, Holst JJ, Drucker DJ, Magnan C, Burcelin R. Physiological and pharmacological mechanisms through which the DPP-4 inhibitor sitagliptin regulates glycemia in mice. Endocrinology 2011; 152:3018-29. [PMID: 21673098 DOI: 10.1210/en.2011-0286] [Citation(s) in RCA: 124] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Inhibition of dipeptidyl peptidase-4 (DPP-4) activity improves glucose homeostasis through a mode of action related to the stabilization of the active forms of DPP-4-sensitive hormones such as the incretins that enhance glucose-induced insulin secretion. However, the DPP-4 enzyme is highly expressed on the surface of intestinal epithelial cells; hence, the role of intestinal vs. systemic DPP-4 remains unclear. To analyze mechanisms through which the DPP-4 inhibitor sitagliptin regulates glycemia in mice, we administered low oral doses of the DPP-4 inhibitor sitagliptin that selectively reduced DPP-4 activity in the intestine. Glp1r(-/-) and Gipr(-/-) mice were studied and glucagon-like peptide (GLP)-1 receptor (GLP-1R) signaling was blocked by an i.v. infusion of the corresponding receptor antagonist exendin (9-39). The role of the dipeptides His-Ala and Tyr-Ala as DPP-4-generated GLP-1 and glucose-dependent insulinotropic peptide (GIP) degradation products was studied in vivo and in vitro on isolated islets. We demonstrate that very low doses of oral sitagliptin improve glucose tolerance and plasma insulin levels with selective reduction of intestinal but not systemic DPP-4 activity. The glucoregulatory action of sitagliptin was associated with increased vagus nerve activity and was diminished in wild-type mice treated with the GLP-1R antagonist exendin (9-39) and in Glp1r(-/-) and Gipr(-/-) mice. Furthermore, the dipeptides liberated from GLP-1 (His-Ala) and GIP (Tyr-Ala) deteriorated glucose tolerance, reduced insulin, and increased portal glucagon levels. The predominant mechanism through which DPP-4 inhibitors regulate glycemia involves local inhibition of intestinal DPP-4 activity, activation of incretin receptors, reduced liberation of bioactive dipeptides, and activation of the gut-to-pancreas neural axis.
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Affiliation(s)
- Aurélie Waget
- Institut de Recherche sur les Maladies Métaboliques et Cardiovasculaires de l'Hôpital Rangueil, Inserm U1048, BP 84225, 31432 Toulouse Cedex 4, France
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Pillot B, Duraffourd C, Bégeot M, Joly A, Luquet S, Houberdon I, Naville D, Vigier M, Gautier-Stein A, Magnan C, Mithieux G. Role of hypothalamic melanocortin system in adaptation of food intake to food protein increase in mice. PLoS One 2011; 6:e19107. [PMID: 21544212 PMCID: PMC3081342 DOI: 10.1371/journal.pone.0019107] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2011] [Accepted: 03/16/2011] [Indexed: 02/01/2023] Open
Abstract
The hypothalamic melanocortin system—the melanocortin receptor of type 4 (MC4R) and its ligands: α-melanin-stimulating hormone (α-MSH, agonist, inducing hypophagia), and agouti-related protein (AgRP, antagonist, inducing hyperphagia)—is considered to play a central role in the control of food intake. We tested its implication in the mediation of the hunger-curbing effects of protein-enriched diets (PED) in mice. Whereas there was a 20% decrease in food intake in mice fed on the PED, compared to mice fed on an isocaloric starch-enriched diet, there was a paradoxical decrease in expression of the hypothalamic proopiomelanocortin gene, precursor of α-MSH, and increase in expression of the gene encoding AgRP. The hypophagia effect of PED took place in mice with invalidation of either MC4R or POMC, and was even strengthened in mice with ablation of the AgRP-expressing neurons. These data strongly suggest that the hypothalamic melanocortin system does not mediate the hunger-curbing effects induced by changes in the macronutrient composition of food. Rather, the role of this system might be to defend the body against the variations in food intake generated by the nutritional environment.
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Affiliation(s)
- Bruno Pillot
- Institut National de la Santé et de la Recherche Médicale, U855, Lyon, France
- Université de Lyon, Lyon, France
- Université Lyon I, Villeurbanne, France
| | - Céline Duraffourd
- Institut National de la Santé et de la Recherche Médicale, U855, Lyon, France
- Université de Lyon, Lyon, France
- Université Lyon I, Villeurbanne, France
| | - Martine Bégeot
- Institut National de la Santé et de la Recherche Médicale, U855, Lyon, France
- Université de Lyon, Lyon, France
- Université Lyon I, Villeurbanne, France
| | - Aurélie Joly
- Université Paris Diderot, Unit of Functional and Adaptive Biology (EAC4413), Paris, France
| | - Serge Luquet
- Université Paris Diderot, Unit of Functional and Adaptive Biology (EAC4413), Paris, France
| | - Isabelle Houberdon
- Institut National de la Santé et de la Recherche Médicale, U855, Lyon, France
- Université de Lyon, Lyon, France
- Université Lyon I, Villeurbanne, France
| | - Danielle Naville
- Institut National de la Santé et de la Recherche Médicale, U855, Lyon, France
- Université de Lyon, Lyon, France
- Université Lyon I, Villeurbanne, France
| | - Michèle Vigier
- Institut National de la Santé et de la Recherche Médicale, U855, Lyon, France
- Université de Lyon, Lyon, France
- Université Lyon I, Villeurbanne, France
| | - Amandine Gautier-Stein
- Institut National de la Santé et de la Recherche Médicale, U855, Lyon, France
- Université de Lyon, Lyon, France
- Université Lyon I, Villeurbanne, France
| | - Christophe Magnan
- Université Paris Diderot, Unit of Functional and Adaptive Biology (EAC4413), Paris, France
| | - Gilles Mithieux
- Institut National de la Santé et de la Recherche Médicale, U855, Lyon, France
- Université de Lyon, Lyon, France
- Université Lyon I, Villeurbanne, France
- * E-mail:
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Mutel E, Abdul-Wahed A, Ramamonjisoa N, Stefanutti A, Houberdon I, Cavassila S, Pilleul F, Beuf O, Gautier-Stein A, Penhoat A, Mithieux G, Rajas F. Targeted deletion of liver glucose-6 phosphatase mimics glycogen storage disease type 1a including development of multiple adenomas. J Hepatol 2011; 54:529-37. [PMID: 21109326 DOI: 10.1016/j.jhep.2010.08.014] [Citation(s) in RCA: 108] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2010] [Revised: 07/28/2010] [Accepted: 08/31/2010] [Indexed: 01/02/2023]
Abstract
BACKGROUND AND AIMS Glycogen storage disease type 1a (GSD1a) is an inherited disease caused by a deficiency in the catalytic subunit of the glucose-6 phosphatase enzyme (G6Pase). GSD1a is characterized by hypoglycaemia, hyperlipidemia, and lactic acidosis with associated hepatic (including hepatocellular adenomas), renal, and intestinal disorders. A total G6pc (catalytic subunit of G6Pase) knock-out mouse model has been generated that mimics the human pathology. However, these mice rarely live longer than 3 months and long-term liver pathogenesis cannot be evaluated. Herein, we report the long-term characterization of a liver-specific G6pc knock-out mouse model (L-G6pc(-/-)). METHODS We generated L-G6pc(-/-) mice using an inducible CRE-lox strategy and followed up the development of hepatic tumours using magnetic resonance imaging. RESULTS L-G6pc(-/-) mice are viable and exhibit normoglycemia in the fed state. They develop hyperlipidemia, lactic acidosis, and uricemia during the first month after gene deletion. However, these plasmatic parameters improved after 6 months. L-G6pc(-/-) mice develop hepatomegaly with glycogen accumulation and hepatic steatosis. Using an MRI approach, we could detect hepatic nodules with diameters of less than 1 mm, 9 months after induction of deficiency. Hepatic nodules (1 mm) were detected in 30-40% of L-G6pc(-/-) mice at 12 months. After 18 months, all L-G6pc(-/-) mice developed multiple hepatocellular adenomas of 1-10 mm diameter. CONCLUSIONS This is the first report of a viable animal model of the hepatic pathology of GSD1a, including the late development of hepatocellular adenomas.
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Affiliation(s)
- Elodie Mutel
- Institut National de la Santé et de la Recherche Médicale, U855, Lyon F-69008, France
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Mithieux G. Brain, liver, intestine: a triumvirate to coordinate insulin sensitivity of endogenous glucose production. DIABETES & METABOLISM 2010; 36 Suppl 3:S50-3. [DOI: 10.1016/s1262-3636(10)70467-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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A retrospective review of the roles of multifunctional glucose-6-phosphatase in blood glucose homeostasis: Genesis of the tuning/retuning hypothesis. Life Sci 2010; 87:339-49. [PMID: 20603134 DOI: 10.1016/j.lfs.2010.06.021] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2010] [Revised: 05/20/2010] [Accepted: 06/29/2010] [Indexed: 01/30/2023]
Abstract
In a scientific career spanning from 1955 to 2000, my research focused on phosphoenolpyruvate carboxykinase and glucose-6-phosphatase. Grounded in basic enzymology, and initially pursuing the steady-state rate behavior of isolated preparations of these critically important gluconeogenic enzymes, our key findings were confirmed and extended by in situ enzyme rate experiments exploiting isolated liver perfusions. These efforts culminated in the discovery of the liver cytosolic isozyme of carboxykinase, known today as (GTP)PEPCK-C (EC4.1.1.32) and also revealed a biosynthetic function and multicomponent nature of glucose-6-phosphatase (EC3.1.3.9). Discovery that glucose-6-phosphatase possessed an intrinsically biosynthetic activity, now known as carbamyl-P:glucose phosphotransferase - along with a deeper consideration of the enzyme's hydrolytic activity as well as the action of liver glucokinase resulted in the evolution of Tuning/Retuning Hypothesis for blood glucose homeostasis in health and disease. This THEN & NOW review shares with the reader the joy and exhilaration of major scientific discovery and also contrasts the methodologies and approaches on which I relied with those currently in use.
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Delaere F, Magnan C, Mithieux G. Hypothalamic integration of portal glucose signals and control of food intake and insulin sensitivity. DIABETES & METABOLISM 2010; 36:257-62. [PMID: 20561808 DOI: 10.1016/j.diabet.2010.05.001] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2010] [Accepted: 05/05/2010] [Indexed: 11/18/2022]
Abstract
Glycolysis is an essential metabolic function that lies at the core of any cellular life. Glucose homoeostasis is, thus, a crucial physiological function of living organisms. A system of plasma glucose-sensing in the portal vein plays a key role in this homoeostasis. Connected to the hypothalamus via the peripheral nervous system, the system allows the body to adapt its response to any variation of portal glycaemia. The hypothalamus controls food intake (exogenous glucose supply) and hepatic glycogenolysis (endogenous glucose supply). Intestinal gluconeogenesis, via the release of glucose into the portal vein, plays a key role in the control of hunger and satiety, and of endogenous glucose production through the modulation of liver insulin sensitivity. The induction of intestinal gluconeogenesis provides a physiological explanation for the satiety effects induced by protein-enriched diets. In particular, the influence of protein-enriched diets on the hypothalamus is comparable to the activation observed after glucose infusion into the portal vein. The induction of intestinal gluconeogenesis also offers an explanation for the early improvement in glycaemia control observed in obese diabetic patients treated by gastric-bypass surgery. In addition to intestinal gluconeogenesis, a number of gastrointestinal hormones involved in the control of food intake exert their effects, at least in part, via the peripheral afferent nervous system. These data emphasize the importance of the gut-brain axis in the understanding and treatment of obesity and type 2 diabetes.
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Affiliation(s)
- F Delaere
- Inserm U855, Institut national de la santé et de recherche médicale, faculté de médecine Laennec, rue Guillaume-Paradin, 69372 Lyon cedex 08, France
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Aschenbach JR, Steglich K, Gäbel G, Honscha KU. Expression of mRNA for glucose transport proteins in jejunum, liver, kidney and skeletal muscle of pigs. J Physiol Biochem 2010; 65:251-66. [PMID: 20119820 DOI: 10.1007/bf03180578] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2009] [Indexed: 01/12/2023]
Abstract
Although pigs are adapted to starch-rich diets and have high turnover rates of glucose, very scarce information is available on the molecular basis of glucose transport. Therefore, the present study attempted a systematic screening for the presence of mRNA of glucose transport proteins in main organs of glucose absorption, production and conservation. From the members of the solute carrier family SLC5A (sodium glucose cotransporter), the porcine jejunum was positive for SGLT1 and SGLT3, but also contained detectable levels of SGLT5. Liver contained SGLT1, SGLT5, traces of SGLT3 and, in one of five pigs, SGLT2. Kidney contained SGLT1, SGLT2, SGLT3, SGLT5 and hardly detectable levels of SGLT4. Skeletal muscle showed weak signals for SGLT3 and SGLT5. Screening for members of the SLC2A family (facilitated glucose transporter) in intestine revealed the presence of mRNA for GLUT1, GLUT2, GLUT5, GLUT7 and GLUT8, while GLUT3, GLUT4, GLUT10 and GLUT11 were also detectable. The liver contained GLUT1, GLUT2 and GLUT8 mRNA, while GLUT3, GLUT4, GLUT5, GLUT10 and GLUT11 were poorly detectable. The kidney was positive for GLUT1, GLUT2, GLUT5, GLUT8 and GLUT11, but traces of GLUT3, GLUT4 and GLUT10 could also be detected. Skeletal muscle had the strongest signal for GLUT4, while GLUT1, GLUT3, GLUT5, GLUT8, GLUT10 and GLUT11 showed weak signals. A total of 12 unique partial cDNA sequences were submitted to GenBank. In conclusion, this study provides molecular insight into the organ-specific expression of glucose transporters in pigs and thus sheds light on the way of glucose handling in this omnivorous species.
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Affiliation(s)
- J R Aschenbach
- Institute of Veterinary Physiology, University of Leipzig, An den Tierkliniken 7, D-04103 Leipzig, Germany.
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Mithieux G. A novel function of intestinal gluconeogenesis: Central signaling in glucose and energy homeostasis. Nutrition 2009; 25:881-4. [DOI: 10.1016/j.nut.2009.06.010] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2009] [Revised: 06/17/2009] [Accepted: 06/17/2009] [Indexed: 12/29/2022]
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Mithieux G, Andreelli F, Magnan C. Intestinal gluconeogenesis: key signal of central control of energy and glucose homeostasis. Curr Opin Clin Nutr Metab Care 2009; 12:419-23. [PMID: 19474723 DOI: 10.1097/mco.0b013e32832c4d6a] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE OF REVIEW It has been established that the gut is much more than a digestive tract. It has the capacity to participate in the control of energy homeostasis via the secretion of various hormones. It can also contribute to the control of glucose homeostasis via its high glycolytic capacity and a recently described function, gluconeogenesis. RECENT FINDINGS In addition to its quantitative role in endogenous glucose production, qualitative roles (i.e. central signaling) were recently described for intestinal gluconeogenesis. In relation to the control of energy homeostasis, intestinal gluconeogenesis, via its detection by a hepatoportal glucose sensor, is able to generate a central signal of control of food intake, resulting in enhanced satiety. This mechanism has been suggested to account for the well known satiety effect initiated by food protein. In relation to the control of glucose homeostasis, intestinal gluconeogenesis has been suggested to be a key factor of the central enhancement of insulin sensitivity for the whole body. It may especially account for the rapid amelioration of the parameters of insulin resistance occurring after gastric bypass, a specific type of surgery of obesity. SUMMARY These new findings on the role of intestinal gluconeogenesis in the central control of energy and glucose homeostasis should be of interest for nutritionists and diabetologists. They pave the way to envision new strategies of prevention or treatment of obesity and type 2 diabetes in humans.
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Affiliation(s)
- Gilles Mithieux
- Institut National de la Santé et de la Recherche Médicale, U855, Université de Lyon, Lyon, France.
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